| Abstract Scope |
The use of ceramic particles like TiC to surface functionalize aluminum powders has emerged as a strategy to induce columnar-to-equiaxed transition of the microstructure and prevent hot tearing in Laser Powder Bed Fusion (L-PBF) of high-strength aluminum alloys. This study examined the impact of the powder surface functionalization with TiC particles in three sizes (45 nm, <4 μm, and 44 μm) and concentrations (1, 2, and 4 wt.%) on the physical and rheological properties of AA2017 powder. Smaller particles and higher concentrations reduced laser reflectance but caused agglomeration, hampering flowability and apparent density, while coarse TiC particles improved significantly the flowability compared to the gas-atomized powder. Rheological tests showed that functionalized powders had reduced cohesion and improved flow behavior under shear condition. Overall, adding 1 wt.% TiC (regardless of size) enhanced powder flowability, laser absorption, and apparent density compared to the gas-atomized AA2017 powder, making it optimal for L-PBF processing. |